Ignition device



4, 1941- L. M. P. DAVISON arm. 2,230,234

IGNITION DEVICE Filed D06. 5 1939 2 Sheets-Sheet 1 Feb. 4, 1941.

L. M. P. DAVISON arm.

IGNITION DEVICE Filed Dec. 5 1939 2 Sheets-Sheet 2 n" K I fill lliIl/lllioi; I. III a lllll I IIIr/IIIIIQII III:

A TTOR/VE) Patentedl='eb.4,1941' I h f 7 2,230,234

arena erse:

'rsnrrrou nation Lemuel Montae Fools Dayison, Ronald Russel McNaughton, and Robert Bainbrldge, Trail, British Columbia,- @anada, assignors to The Consolidated Mig and smelting Company of Canada, Limited, Montreal, Quebec, @anada', a company of Canada Application December 5, 1939, Serial. No. 3 t7,658

6 Claims. (01. 266-21) This invention relates to an improved ignition and assemble the ignition device in a simple mandevice for initiating combustion in a layer of'mancr so as to. eliminate the need for separateacterial to be 'sintered and. is particularly applituating mechanism and, as far as'possible, any

-'- cable for use rlnconjunctlon with continuous, source of mechanical failure.

down-draft, sint'ering apparatus operating on the, An understanding of the manner in which we 5 general principles of the Dwight-Lloyd sintering attain the objects of our invention may be had machinel from the following-description and. accompany- In the. Dwight-Lloyd process of sintering. ores, i'ng drawings in whichthe ignition device, burn wheeled pallets, each having a grate bottom, are ing -aliquid fuel, is described as applied inconcaused to travel along a. continuous track. Each, j o W thi the W 1- known Dw oy lll' pallet passes progressively under a feed hopper, straight-line, continuous, sintering Ina-chine, but from which it receives its charge, thence under which may obviously be adapted to other types of an ignition device, by means of which the surface ,Sintering pp s a d to solid or gaseous fu l of the charge is ignited, and thence over a uc- Figure l is a side elevation of. a Dwight-Lloyd tion wind box where air is drawn through the straight-line sintering machine embodying our 15 charge into the box to maintain combustion. 1 ignition e; When sinterlng any material, the operation is Figure 2 s an end elevation S n n otted initiated by igniting the combustible material at e e e t f t e transverse movement of the surface of the charge as completely as post e ignition device across the pa t;

sible, such as by applying a, flame thereto for a Figure 3 is a top plan view of the oscillating 20 brief period of time, after which, combustion is mefihanism;

propagated through the layer by the air curgure 4 is a section along the line l rents drawn therethrough. Ignitlon'is usually effected by means of a stationary muffle burning Figure 5 s an end e io of Figure 4; and

coal, coke breeze, oil or gas and by directing the u e 6 is an enlarged view of the liq d fuel 25 flame over the whole width of the moving charge. burner and enclosing hood, Shown P t y in cross The burner is usually placed at one side of the Sectionmachine and the flame is i t across the Like reference characters refer to like parts lets at right angles to their movement. throughout e Specification gs- The tationary ignition devices used hereto- The numeral I indlcates a continuous, down- 30 I fore, wherein the burner is placed at one side of draft, Straight-line s teri machine of the the machine, have certain disadvantages inas- Dwight-Lloyd p P e w independent much as the flame must be of a m m; length and unconnected pallets 2 moved in'an endless to extend across the entire surface of the charge train by Sprockets 3 under the feeding ppe in the pallets and the flame, not being of uniform 4, der the ignition device 5 and over the suc- 35 temperature throughout its length, causes irreg- 151.011 boxes 5 respectively Each P et 2 is DrO ularlties in ignition and distribution and a relavlded with Wheels on which it moves cept when tively high heat loss due to radiation, thus causpassin ver t e Suction boxes, at which time it ing an unnecessarily high consumption of fuel. slides on its planed bottom Over the planed mp 40 A further difficulty is that of uniformly igniting 0f the Suction boxes in Substantially air e ng the charge when it presents an uneven surface engagement therewith Dead p es a e 'proto the flame. vided at each end of the suction boxes over the The principal object of the present invention is planed surfaces of wh c each pallet must move to provide an ignition device adapted to overcome and which P t t e lea age of air into the the disadvantages inherent in the stationary Suction boxes at t e Po ts- 45 type burner, thereby effecting substantial savings e ignition device 5 s s ed to oscillate in in fuel consumption. We have attained that oba hendulum-like manner O er the surface of the ject by developing an oscillating, vertical-type c r i t e pa e s at right angles to the diburner designed to move at a. uniform rate of motion of movement of the pallets.

speed across the surface of the charge contained The ignition device consists o the liquid fuel in the pellets and which will initiate, during its ur er 0, suitably connected to air and liquid movement, the combustion of the surface layers fuel lines II and I respectively. The air and of the material to be sintered by means of a short liquid fuel lines are flexibly connected to their hot flame. sources of supply, preferably by means of rub- A further object of the invention is to construct ber hose which permit their free oscillation. No

- special design of burner is for the ig-- nition of the fuel, but we have found that very satisfactory results are obtained from a type of burner in which a spiral vane is set to promote atomization of fuel, and mixing of fuel and com bustion air, and which produces a turbulent,

short, high temperature flame. The burneris enclosed in a hood I8, preferably lined with flre resistant material, as illustrated in Figure .8.

The burner I 0 and enclosing hood are oscillated in a pendulum-like manner by the rotation of cam 8 which is mounted on and rotated by weight it. The action of counterweight II holds cam follower 8 against cam 8 during its rotation, and thus prevents the ignition device from moving independently of the rotation of earn 8, at any point in its oscillation.

Cam shaft 1 is preferably rotated by the mechanism which drives the sintering machine, such as through a chain drive from the feeder mechanism as illustrated in Figures 1 and 2.. The relationship between the forwardmovement of each pallet and the transverse oscillation of the ignition device will thus be constant, such relationship being determinable by the type of charge being sintered, and readily adjusted to suit specific conditions.

As we prefer to ignite the charge in only one direction of the movement of the ignitionv device, cam 8 is designed to press against cam follower 9 progressively and uniformly forwardly from the point marked X, Figure 4, to the point marked Y, approximately, at which latter point the ignition device will have reached its maximum distance'from the vertical. Cam 8 is further designed from point Y to point x to effect the return motion of the device as rapidly as possible. The alternate uniform forward and rapid return motion of the ignition device is, of course, aided by the action of counterweight it which causes cam follower 9 to be retained against cam 8 during its complete rotation.

The most suitable angle at which the flame is impinged on the surface of the charge is readilydeterminable in practice. For example, we have found that a 40 angle between the burner axis and the surface of the charge is satisfactory.

In the operation of our ignition device, we have found it possible to reduce considerably the amount of fuel normally required by the stationary type of burner to ignite the surface of the charge contained in the pallets. In addition, it is possible'to efl'ect the uniform ignition of the surface of the charge regardless of irregularities in the surface. i

It will be understood, of course, that modifications may bemade to the specific embodiment of our invention, hereinbefore described and illustrated, to incorporate the principles thereof in other types of sintering apparatus without departing from the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent of the United States is:

1. In a continuous, down-draft sintering ma- 2,aso,as4 v a chine including a'feed hopper adapted to feed a charge of material into each of a train of ir oving pallets, an ignition device comprising a flex ibly suspended fuel burner an enclosing hood,

means for oscillating said burner-f"transversely.

over the surface of the charge contained pallet as itmoves' said burner;su dxoscil- .I

I lating adapted tqrmove saidtburne r at a uniform rate of speed!!! one directionof its oscillation and at'an'jacceleratedjrate of in the opposite direction.f r

2. In a continuous, down-draft sintering machine including a feed hopper adapted to feed a charge'of material intov eachof a'train of moving pallets. an ignition device comprising a flexibly suspended burner and enclosing hood, and rotatable cam means adapted to oscillate said burner in a pendulum-like manner transversely over the surface of the charge contained in each pallet as it moves under said burner.

3. In a continuous, down-draft sintering machine including a feed hopper adapted to feed a charge of material into each of a train of moving pallets, an ignition device comprising a flexibly suspended burner and enclosing hood, rotatable cam means adapted to oscillate said burner in a pendulum-like manner transversely over the surface of the charge contained in each pallet as it moves under said burner, and counterweight means adapted to prevent said burner from swinging freely from its flexible suspension.

4. In a continuous, down-draft sintering machine including a feed hopper adapted to feed a charge of material into each of a train of moving pallets, an ignition device comprising a flexibly suspended liquid fuel burner and enclosing hood, a rotatable cam adapted to be in continuous contact with a cam follower secured to said suspension means and counterweight means adapted to prevent said burner from swinging freely from its flexible suspension.

5. In a continuous, down-draft sintering machine including a feed'hopper adapted to feed a charge of material into each of a train of moving pallets, an ignition device comprising a flexibly suspended liquid fuel burner and enclosing hood, a rotatable cam adapted to be in continuous contact with a cam follower secured to said suspension means, counterweight means adapted to prevent said burner from swinging freely from its flexible suspension and means for synchronizing the rotation of said cam with the forward movement of each of said pallets.

6. In a continuous, down-draft sintering machine including a feed hopper adapted to feed a charge of material into each of a train of moving pallets. an ignition device comprising a flexibly suspended fuel burner and enclosing hood, a rotatable cam adapted to be in continuous contact with a ca m follower secured to said suspension means, said cam being designed to impart a relatively uniform forward movement and accelerated return movement to said fuel burner transversely to the direction of the movement of the charge and counterweight means adapted to prevent said burner from swinging freely from its flexible suspension. LEMUEL MONTAGUE POOLE DAVISON. RONALD RUSSEL McNAUGHTON. 7 ROBERT BAINBRIDGE. 

